Google's driverless car

California Jerry Brown rides a driverless car to Google headquarters in Mountain View, Calif., where he signed a bill establishing safety and performance regulations to test and operate such vehicles in the state on Tuesday, Sept. 25, 2012. Google has been testing a fleet of such computer-controlled vehicles for several years.

California Gov. Jerry Brown, front left, rides in a driverless car to a bill signing at Google headquarters in Mountain View, Calif. Consumers may be able to own and operate a driverless car by 2017, according to Google. Several states have begun debating legislation on driverless cars.

Google co-founder Sergey Brin looks on during a news conference at Google headquarters on Sept. 25, 2012 in Mountain View, Calif. California Gov. Jerry Brown signed a bill allowing driverless cars to be tested on public roads.

(Credit: Getty Images)

California Gov. Jerry Brown looks on as Google co-founder Sergey Brin speaks during a news conference at Google headquarters on Sept. 25, 2012, in Mountain View, Calif. Brown signed a bill allowing driverless cars to be tested on public roads.

(Credit: Getty Images)

California Gov. Jerry Brown signs a bill allowing driverless cars to be tested on public roads as state Sen. Alex Padilla and Google co-founder Sergey Brin look on at the Google headquarters on Sept. 25, 2012 in Mountain View, Calif.